Outside tap help

[FiremanT]

I've decided to send back the kit and build the tap from various parts including those recommended. I have a couple of questions regarding fittings. I already have an isolation valve the other side of an 1/2 inch male thread which then leads to the mains copper pipe. I plan attach my outside tap piping to this 1/2 inch male thread. First of all I'll need to change the direction of the pipes by 90 degrees. Do I need a 1/2 inch male to 1/2 inch female elbow for this? I can't seem to find one in screwfix. Also, can I buy a drain cock which will thread onto (or just before) the elbow? Or alternatively could I use a 3 way female tee and thread the drain cock onto this? Thanks in advance!

So is this an isolation valve with a 1/2" male thread. That is to say is the valve and thread all part of tthe same thing. Like:

If so, the "1/2" thread" is probably a 15 mm compression. Get a nut and olive and run the 15 mm tibe from that. Does the valve turn okay.? They are often jammed in position. If so, remove and replace with proper stopcock, assuming it will be out of sight.
Use a 15mm tee with a 15mm drain cock. If you are anticipating using it to drain over winter, I would suggest using an isolation valve, as above, after the tee, and insert the drain cock innto the valve. Drain cocks are probably the worst designed plumbing component, and always fail. By sticking in a seperate valve, it is easy to isolate, remove the cock, drain off via the valve and reseal. Alternatively, use a compression tee, again to enable simple removal of the cock.